// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_HOST_ZOOM_LEVEL_CONTEXT_H_
#define CONTENT_BROWSER_HOST_ZOOM_LEVEL_CONTEXT_H_

#include <memory>

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "content/browser/host_zoom_map_impl.h"
#include "content/public/browser/zoom_level_delegate.h"

namespace content {
struct HostZoomLevelContextDeleter;

// This class manages a HostZoomMap and associates it with a ZoomLevelDelegate,
// if one is provided. It also serves to keep the zoom level machinery details
// separate from the owning StoragePartitionImpl.
class HostZoomLevelContext
    : public base::RefCountedThreadSafe<HostZoomLevelContext,
          HostZoomLevelContextDeleter> {
public:
    explicit HostZoomLevelContext(
        std::unique_ptr<ZoomLevelDelegate> zoom_level_delegate);

    HostZoomMap* GetHostZoomMap() const { return host_zoom_map_impl_.get(); }
    ZoomLevelDelegate* GetZoomLevelDelegate() const
    {
        return zoom_level_delegate_.get();
    }

protected:
    virtual ~HostZoomLevelContext();

private:
    friend class base::DeleteHelper<HostZoomLevelContext>;
    friend class base::RefCountedThreadSafe<HostZoomLevelContext,
        HostZoomLevelContextDeleter>;
    friend struct HostZoomLevelContextDeleter;

    void DeleteOnCorrectThread() const;

    std::unique_ptr<HostZoomMapImpl> host_zoom_map_impl_;
    // Release the delegate before the HostZoomMap, in case it is carrying
    // any HostZoomMap::Subscription pointers.
    std::unique_ptr<ZoomLevelDelegate> zoom_level_delegate_;

    DISALLOW_COPY_AND_ASSIGN(HostZoomLevelContext);
};

struct HostZoomLevelContextDeleter {
    static void Destruct(const HostZoomLevelContext* context)
    {
        context->DeleteOnCorrectThread();
    }
};

} // namespace content

#endif // CONTENT_BROWSER_HOST_ZOOM_LEVEL_CONTEXT_H_
